Casting ring



Oct. 9, 1934. w, I CARPENTER 1,976,655 I I CASTING RING Filed July 3, 1933 ml. 22 ]f 1 17 3 Z1 r 20 #2 4/1 v. I A Pig TI Zsi'er I. Uar a eniier Patented Oct. 9, 1934 v UNITED STATES PATENT OFFE'C 1,976,655 CASTING RING Webster I. Carpenter, Norfolk, Va.

Application July 3, 1933, Serial No. 678,965 1 Claim. (Cl. 22-1131) This invention relates to a casting ring designed primarily for use in connection with centrifugal casting machines employed by dentists when molding dental work, butit is to be understood that the ring, in accordance with this invention may be employed in any connection for which it may be found applicable, and the invention has for its object to provide, a casting ring so constructed and arranged to prevent breakage of an investment carried thereby on theexpansion and contraction of the ring. I

A further object of the invention is to provide, in a manner as hereinafter set forth, a casting ring for the purpose referred to having means, which when the ring expands'lengthwise and laterally acts to retain therein an investment in which a mold or molds is or are formed and further providing for maintaining the bottom of such investment always flush with the bottom edge of the ring.

A further object of the invention is to provide, in a manner as hereinafter set forth, a casting ring so constructed and arranged to prevent, on the expansion and contraction thereof the disconnecting, splitting, breaking or damaging of an investment secured therewith.

A further object of the invention is to provide, a combined casting ring and investment; the ring being formed in a manner to prevent, on the expansion and contraction thereof the damaging or disconnection of the investment; the investment being formed with a'molding means and a sprue-means leading from one end thereof for conducting molten metal to the molding means, and with said end provided with means acting to support a metal body to be melted and to arrest the shifting of the metal to an extent, when the casting ring and investment are carried around with a rotatable element of a casting machine, to not prevent and to facilitate the molten metal entering the sprue-means.

To the above ends essentially, and to others which may hereinafter appear the invention consists of such parts, and such combination of parts which fall within the scope of the invention as claimed.

The casting ring may be of any cross-sectional contour desired, and is shown by way of example as being of circular, oval and square contour.

In the drawing:

Figure 1 is a vertical sectional view of the casting ring and an investment arranged in the latter, the ring being of circular cross-section.

Figure 2 is a vertical sectional view of the casting ring when set up as of circular form.

Figure 3 is a top plan viewof thecasting when set up asof circularcontour.

Figure 4 is a top plan view of the casting ring when set up as of square contour.

Figure 5 is a top plan ,view of the casting ring when set up as of oblong form; The body of the casting ring may beof any suitable height and internal area, as well as of any desired thickness.

With reference to Figures 1, 2 and 3, the ring generally indicated at 1 consists of an annular, body 2 of sleeve-like form open at each end. The end edges of body 2 are designated at 3, 4. The inner face of,body 2 below its transverse median, thereof and spaced from end edge 4 is formed with a portion of reduced thicknessand a pair-of spaced oppositely beveled facets to provide there-j inan endless groove 5 provided with an inner or base wall 6, an upper side wall '7 and a lower side wall 8. The walls 7, 8 merge at their inner ends into the top and bottom ends respectively of the wall 6. The Wall 7 extends upwardly throughout from its innerend towards the axis and edge 3 of body 2. The wall 8 extends downwardly throughout from its inner end towards the axis and edge 4 of body 2. The heightror cross-sectional length of wall 6 is materially greater than the cross-sectional length of either wall ,7, 8. Preferably the height or cross-sectional length of wall .6 will correspond to or be greater than the combined cross-sectional lengths, of the Walls '7; 8. The outer end of wall 7 is arranged below the transverse median of body 2. The outerend ring of wall 8 is positioned in close proximity to edge 4 of body 2. I I The ring 9 shown in Figure 4 is of square cross: section and provided with an endless groove 10 on its inner face. The groove 10 is set up in the same manner as the groove 5, that is to say the inner, upper and lower walls of groove 10 will be set up in the same manner as the walls of the groove 5. Groove 10 will be located on ring 9 at a point corresponding to the point at which groove 5 is located on ring 1.

The ring 11 shown in Figure 5 is of oval cross section and is provided with an endless groove 11' on its inner face. The groove 11' is set up in the same manner as groove 5, that is to say the inner, upper and lower walls of groove 11 will be set up in the same manner as the walls of groove 5. Groove 11 will be located on ring 11 at a point corresponding to the point at which groove 5 is located on ring 1.

Preferably the depth of each groove will correspond to half the thickness of the body of the ring. The function of the oppositely inclined or beveled top and bottom wall of each groove, as well as the purpose of each groove will be presently referredto.

,With reference to Figure 1, the ring 1 has arranged therein an investment 12 which has its lower end or bottom 13 flush with bottom edge 4 of body 2. The upper end or top 14 of investment 12 is arranged below the top edge 3-of' body 2. The investment 12 may be provided with sprue-means and one or more molds and is shown by way of example as being provided with a'sprue 15 and a mold 16 in which the inner end of sprue 15 opens. The outer end of the latter is arranged at endor top 14 of investment 12.

The upper end portion of the investment is in.

Vdicated at 20'and is formed with a plurality of superposed stepped endless risers 2l 'lea'ding to and merging into a plurality of superposed stepped endless horizontal shoulders 22 inclining to the upper end of a lower riser.

downwardly from the lower end of an upper riser The lowermost shoulder surrounds and merges at its inner side into the top of the wall of theconcavity I8; The

lower riser atitsbottom surrounds and merges into the portion 18. The risers prevent the shifting of the body of metal 18 to an extent, when the investment and ring is carried by the rotatable element of a casting machine to prevent it being swung from off the investment and the risers and shoulders facilitate the molten metal to travel in a direction to enter the sprue 15 for the con ducting of the metal to the mold'16. As is well known in dentistry, when castingv piece of'dental work, the body of metal 19 is arranged upon the top l 4of the investment. The ring and investment are then mounted within a suspension structure which is supported from the rotatable element of a centrifugal castingamachine. After being so positioned, the metal body is subjected to intense heat to melt it. The application of the heat expands the ring and unless provision is made for securing the investment in the ring, the expansion of the latter loosens the investment to a material extent, thereby caus ing pounding between it and the ring when-the latter is carried with the rotating element of 'a casting machine resultingin cracking, breaking and damaging of the investment. Further provision must also be had to provide for'the investment shifting relative to the ring to position the bottom of the investment flush with the bottom of the ring during the expansion of the latter so as to prevent cracking, breaking or damage'to the investment. The rings referred to are of a construction to overcome the objections just referred to. The investment is anchored to a ring in accordance with this invention, by a laterally extending portion 23 on the periphery thereof filling the groove on the inner face of the ring. The oppositely angled side walls of the grooves permit of such lateral portion moving in a direction outwardly with respect to the groove on the expansion of the ring for the purpose of enabling vthe ring. The expansion of the ring lengthwise and laterally is not to an extent which will cause sportion23 to be moved completely clear of the groove and, therefore, the connection between the ring and investment will not be broken thereby preventing; after the heat application to the metal and the ring and investment are carried around with the casting machine until the molten metal'is set, theshiftingof thering land'investment lengthwise relatively to each other. The form of ring referred to provides for the I'bott'oin of" theinvestment to beuflush with thebottom' edge of the ring at all times, so: such bottomand such edge "will 's'imultaneously'b'ear upon that element of the casting machine they are supported by. and which prevents an 'outward thrust of the investment relative to the ring by the centrifugal action of the machine? What I'cIaim is;

An' investment ada-pted to" be encompassedby a casting ring andprovided with a'castin'gcavity and a spruele'ading thereto, said investmentbeing formed at the upper end portion thereof fwith a gate of flared contour, the base ofsaid gate being disposed axially of said investment and 'in the form of a concavityfopeningcentrally thereof into said spru'd'thaJtportion'of said gate-above said concavity being formed with a plurality of endless horizontally'disposed shou ders inclining downwardly towards the axis of the investmentanda'plurality of superposed endless risers incliningfrom their lower ends'in 'a' direction awayfrom the axis of the investment and connecting the inner side of an upper shoulder to theouter side of alowershoulder, the lowermost shoulder merging at its inner side into the upper endof the wall of the concavity,- and the uppermost shoulder being positioned-at the terminus of said end portion. Y WEBSTER I. CARPENTER. 

